The inventive concept relates to storage controllers, storage systems and methods of operating a storage controller.
A redundant array of inexpensive or independent disks (RAID) technology is used to divide data into multiple data sections, distribute and store the divided data sections across multiple disks and may have various levels. For example, in a RAID 5 system, while striping data and storing the striped data onto a plurality of disks in a distributed manner, the data is stored with a parity bit that may be used to recover the data stored on a pertinent disk in the event of a read data failure. The parity bit may be obtained by performing an exclusive-OR (XOR) operation on the striped data. In another example, a RAID 6 system uses first and second parity bits to provide a data recovery capability.
A computational system using RAID usually includes a central RAID controller for controlling a plurality of data storage disks (hereafter, “storage disks” or “storage devices”). The central RAID controller controls the storage devices while processing RAID requests directed to data stored on the storage devices. However, as RAID requests become more frequent, the operating load (or computational overhead) placed upon central RAID controller may increase to the point where performance of the computational system is impaired.